drivers/macintosh/windfarm_lm75_sensor.c

   1 /*
   2  * Windfarm PowerMac thermal control. LM75 sensor
   3  *
   4  * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
   5  *                    <benh@kernel.crashing.org>
   6  *
   7  * Released under the term of the GNU GPL v2.
   8  */
   9
  10 #include <linux/types.h>
  11 #include <linux/errno.h>
  12 #include <linux/kernel.h>
  13 #include <linux/delay.h>
  14 #include <linux/slab.h>
  15 #include <linux/init.h>
  16 #include <linux/wait.h>
  17 #include <linux/i2c.h>
  18 #include <linux/of_device.h>
  19 #include <asm/prom.h>
  20 #include <asm/machdep.h>
  21 #include <asm/io.h>
  22 #include <asm/sections.h>
  23 #include <asm/pmac_low_i2c.h>
  24
  25 #include "windfarm.h"
  26
  27 #define VERSION "1.0"
  28
  29 #undef DEBUG
  30
  31 #ifdef DEBUG
  32 #define DBG(args...)    printk(args)
  33 #else
  34 #define DBG(args...)    do { } while(0)
  35 #endif
  36
  37 struct wf_lm75_sensor {
  38         unsigned int            ds1775 : 1;
  39         unsigned int            inited : 1;
  40         struct i2c_client       *i2c;
  41         struct wf_sensor        sens;
  42 };
  43 #define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens)
  44
  45 static int wf_lm75_get(struct wf_sensor *sr, s32 *value)
  46 {
  47         struct wf_lm75_sensor *lm = wf_to_lm75(sr);
  48         s32 data;
  49
  50         if (lm->i2c == NULL)
  51                 return -ENODEV;
  52
  53         /* Init chip if necessary */
  54         if (!lm->inited) {
  55                 u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(lm->i2c, 1);
  56
  57                 DBG("wf_lm75: Initializing %s, cfg was: %02x\n",
  58                     sr->name, cfg);
  59
  60                 /* clear shutdown bit, keep other settings as left by
  61                  * the firmware for now
  62                  */
  63                 cfg_new = cfg & ~0x01;
  64                 i2c_smbus_write_byte_data(lm->i2c, 1, cfg_new);
  65                 lm->inited = 1;
  66
  67                 /* If we just powered it up, let's wait 200 ms */
  68                 msleep(200);
  69         }
  70
  71         /* Read temperature register */
  72         data = (s32)le16_to_cpu(i2c_smbus_read_word_data(lm->i2c, 0));
  73         data <<= 8;
  74         *value = data;
  75
  76         return 0;
  77 }
  78
  79 static void wf_lm75_release(struct wf_sensor *sr)
  80 {
  81         struct wf_lm75_sensor *lm = wf_to_lm75(sr);
  82
  83         kfree(lm);
  84 }
  85
  86 static const struct wf_sensor_ops wf_lm75_ops = {
  87         .get_value      = wf_lm75_get,
  88         .release        = wf_lm75_release,
  89         .owner          = THIS_MODULE,
  90 };
  91
  92 static int wf_lm75_probe(struct i2c_client *client,
  93                          const struct i2c_device_id *id)
  94 {
  95         struct wf_lm75_sensor *lm;
  96         int rc, ds1775;
  97         const char *name, *loc;
  98
  99         if (id)
 100                 ds1775 = id->driver_data;
 101         else
 102                 ds1775 = !!of_device_get_match_data(&client->dev);
 103
 104         DBG("wf_lm75: creating  %s device at address 0x%02x\n",
 105             ds1775 ? "ds1775" : "lm75", client->addr);
 106
 107         loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
 108         if (!loc) {
 109                 dev_warn(&client->dev, "Missing hwsensor-location property!\n");
 110                 return -ENXIO;
 111         }
 112
 113         /* Usual rant about sensor names not beeing very consistent in
 114          * the device-tree, oh well ...
 115          * Add more entries below as you deal with more setups
 116          */
 117         if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
 118                 name = "hd-temp";
 119         else if (!strcmp(loc, "Incoming Air Temp"))
 120                 name = "incoming-air-temp";
 121         else if (!strcmp(loc, "ODD Temp"))
 122                 name = "optical-drive-temp";
 123         else if (!strcmp(loc, "HD Temp"))
 124                 name = "hard-drive-temp";
 125         else if (!strcmp(loc, "PCI SLOTS"))
 126                 name = "slots-temp";
 127         else if (!strcmp(loc, "CPU A INLET"))
 128                 name = "cpu-inlet-temp-0";
 129         else if (!strcmp(loc, "CPU B INLET"))
 130                 name = "cpu-inlet-temp-1";
 131         else
 132                 return -ENXIO;
 133
 134
 135         lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
 136         if (lm == NULL)
 137                 return -ENODEV;
 138
 139         lm->inited = 0;
 140         lm->ds1775 = ds1775;
 141         lm->i2c = client;
 142         lm->sens.name = name;
 143         lm->sens.ops = &wf_lm75_ops;
 144         i2c_set_clientdata(client, lm);
 145
 146         rc = wf_register_sensor(&lm->sens);
 147         if (rc)
 148                 kfree(lm);
 149         return rc;
 150 }
 151
 152 static int wf_lm75_remove(struct i2c_client *client)
 153 {
 154         struct wf_lm75_sensor *lm = i2c_get_clientdata(client);
 155
 156         DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name);
 157
 158         /* Mark client detached */
 159         lm->i2c = NULL;
 160
 161         /* release sensor */
 162         wf_unregister_sensor(&lm->sens);
 163
 164         return 0;
 165 }
 166
 167 static const struct i2c_device_id wf_lm75_id[] = {
 168         { "MAC,lm75", 0 },
 169         { "MAC,ds1775", 1 },
 170         { }
 171 };
 172 MODULE_DEVICE_TABLE(i2c, wf_lm75_id);
 173
 174 static const struct of_device_id wf_lm75_of_id[] = {
 175         { .compatible = "lm75", .data = (void *)0},
 176         { .compatible = "ds1775", .data = (void *)1 },
 177         { }
 178 };
 179 MODULE_DEVICE_TABLE(of, wf_lm75_of_id);
 180
 181 static struct i2c_driver wf_lm75_driver = {
 182         .driver = {
 183                 .name   = "wf_lm75",
 184                 .of_match_table = wf_lm75_of_id,
 185         },
 186         .probe          = wf_lm75_probe,
 187         .remove         = wf_lm75_remove,
 188         .id_table       = wf_lm75_id,
 189 };
 190
 191 module_i2c_driver(wf_lm75_driver);
 192
 193 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 194 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
 195 MODULE_LICENSE("GPL");
 196